Method of producing finished fabric



Jan. zo, 1942.

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Patented Jan; 2o, 1942 Clarence T.v Graham, North Attleboro, Mass-,'asf signor to William H. Bannon, Mansfield, Masi.

Application 'August 29, 193s, sei-lama. 227,436 1o claims. (ci. s-nsi This invention relates to the method of producing a new type of finished fabric.

For some time `past the textile weaving mills have produced a fabric, such as marquisette, that is relatively thin and is of an open weave. This fabric carries ypile that consists either of rovings or of yarn, the pile being interengaged with` threads of the ground fabric. Sometimes these rovings or yarn are sheared long and sometimes short. Sometimes they areI formed into spaced dots arranged on the obverse side of the fabric ground. At other times they areotherwise arranged and are of such configuration as to forml various designs. An example of such a fabric is what is commonly known on the market as a fluff dot marquisette.

Since the beginning of the manufacture of this fabric the finishing of the fabric has been somewhat of a problem. It is desirable, of course, at times to dye the fabric, at other times to bleach it, and to stiffen the ground fabric, which Vhas either been bleached or dyed or is yet in the gray.

The problem of stiffening the ground fabric hasv revolved around the possibility of so stifening without destroying or changing the condition of the rovings or yarns that form the pile or the uflv dots. These rovings or yarns, forming the pile k of the various congurations, have in the lpast sometimes been fluifed up after they have been sheared and at other times have been permitted to remain in thecondition that existed after the Heretofore the stiifeningof the ground `of this type of fabric has been purely a mechanical one, that is to say, in the past the .ground fabric has been starched and the penetration of the starch into the fabric arrested before it reached the pile, thus permitting the pile to remain in its soft condition. The disadvantage here of course is that when it is necessary to launder the fabric the water removes the starch from the fabric andv leaves it in a raggy condition. If the fabric is to be restarched athome or by commercial laun known as a permanent finish, that is to say, to impart a nish to the ground fabric that will permit the laundering of the fabric without de'- stroying the hand of the ground and without changingthe original soft, or uffy, condition of the pile or fluff dots.

Icontemplate the finishing of this fabric to y givethe ground a desirable hand" of permanent finish while maintaining the original condition of the pile, that is, its soft and fluffy condition, by applying a chemical agent or agents to the ground fabric, permitting them to remain in the ground fabric for a sufficient length of time to alter its chemical composition, and removing the agent or agents from the ground fabric or neutralizing them before they affect the pile.

I contemplate other steps as will appear in the following description.

I disclose herein drawings for the purpose of iuustraung the manner in which this method may be carried out, in which:

' problem is to finish the ground or give it a han l dries it has been the practice of dipping the fabric in' ya starch solution and laundering as ordinarily light fabric is laundered, which, of course, has re sulted in the application of starch to the pile,

thus destroying the original effect of having a crisp background and a soft fluffy pile.

'Ifhatis as far as the art has advanced today. AMy invention contemplates chemically` changiiig the ground fabric without chemically chang.

ing the pile or affecting the pile in any way and I contemplate a chemical change which will impart to the ground fabric what is commonly Figures 1 and 1A are diagrammatic views of the various combinations of steps that may be e'mployed;

Figure 2 is a plan view of a fabric formed by my process;

Figure 3 is a section of 'the fabric before the dots have been fluffed; and

Figure 4 is a similar view after the dots have l been uffed.

The cotton fabric as it comes from the textile mill consists of a ground I (Figure 2) of the usual 'warp and weft, as are found, for instance, in

cotton marquisettes. Rovings, yarns or threads 2, are interengaged with the ground threads so that the bight'portions 3 of the former are on the reverse side of the ground and the ends are extended from the obverse side of the ground. When this cotton fabric comes from the textile mill to the finishing mill the pile 2 is in the condition shown in Figure 3, generally, so that the without finishing the rovings, yarns or threads that form the pattern forming portions of the obverse side of the ground, and without destroying their natural or created flufliness.

" The inventioncontemplates in one of its stages the finishing of fabric of this nature to retain the vpattern or figure forming portions in their original condition, either as they come from the textile mill or after the fabric has been bleached,

' and also contemplates the imparting of a flufllness 'to the rovings or yarns or threads that form the pattern'or ngure forming portions either before added.

manent finishing of the ground fabric is concerned.

In its most specic detail my process consistsl of steps 1 to 25 (disclosed in the drawings) inclusive, but some of these steps may be omitted and the steps may be rearranged as will later appear.

In carrying out the process the fabric is moved continuously preferably from the beginning to the end of the process.

The steps disclosed in the drawings are:

1. The application of a "retarder to the fibers from which the raised pattern or figure forming portionsV are formed but not tothe ground of the fabric.

2. The drying of the fabric. v

3. The application of an accelerator to the ground but not to the raised pattern or gure forming portions.

4. The drying of the fabric.

5. The application of an acid to the back of the ground fabric.

6. The washing, of the acid from the fabric.

7. The drying of the fabric.

. 8. The application of a retarder as in step No. 1.

9. The drying of the fabric.

10. The application of an accelerator as in step No. 3.

11. The drying of the fabric.

12. The application of' a caustic alkali to the back ofthe ground fabric.

13. The washing of the alkali from the fabric.

14. The drying of the fabric.

15. The application of a retarder as in steps Nos. 1 and 8.

16. The drying of the fabric.

17. The application of an accelerator tothe fabric as insteps Nos.3 and 10.

18. The drying of the fabric.

19. The application of an acid to the back of' from the fabric.

`=2.4. The passing of the moistened fabric through a drying zone while on the tenter frame.

25. The projecting of a nuidsuch as steam or air under pressure on to the fabric to impart a nal uiliness to the raised pattern or figure forming portions.

As an lalternate of steps 6, 13 and 20, the fabric may be subjected instead of to water, to a neutralizing agent to neutralize the acid and. al-

kali that has been' applied to the fabric or, in-.

deed, the fabric may be passed through a water bath to which neutralizing agents have been Definitions .Y

include the well known trade-mark retarder such as Neva-Wet, commercially sold by the Neva- Wet Corporationof America, Inc.; Impregnole,

commercially sold by the Warwick Chemical Company, and other similar compositions may be used.

I also may use a retarder consisting of 50% gum arabic, 48% dextrine and 2% Wax. A, The purpose of the retarder is to render the raised pattern or figure forming portions lessv celerators, such as are commercially sold under the trade-mark Tetranol 1638, commercially sold by the Arkansas Co., Inc., AlkanoL commercially sold by the E. I. Du Pont De Nemours & Co., Inc., or others of the same general character, which fall in the group known as the sulphonated fatty alcohols, or I may use other accelerators, such, for instance, as one made up of approximately forty per cent (40%) pine oil, forty per cent (40%) sulphonated castor oil, and twenty per cent (20%) Cellosolve, commercially sold by the Carbide & Carbon Chemical Corp.

I may also use an accelerator consisting of ten per cent (10%) triethanolamine, forty per cent (40%) pine oil and fty per cent (50%) sulphonated castor oil.

The purpose of the accelerator is to render the ground fabric more susceptible to penetration by moisture; that is to say, it hastens the penetration of the moisture beyond that which normally exists if no accelerator wereV used. The object of the accelerator is directly opposite to that of the retarder.

Acids-' contemplate using many acids or combinations of acids that would change the character of the cotton forming the ground fabric'so that it will be rendered substantially transparent and resilient as distinguished from a dull, transparent or truly parchmentized fabric.

Among these acids are those such as disclosed in the two patents above referred to. For instance, I may use a sulphuric acid of over 501/2" B (not substantially less than 51 13) in the manner and for the reason set forth in the Heberlein Patent 1,439,512, above referred t0.

Or I may use an acid such as set forth inthe Schuttig Patent 1,451,306, above referred to, and for the reasons and in the manner set forth in the said patent. This acid solution, for instance,

is made of nitric acid (100%) 50%, sulphuric acid (100%) 31.6%, water 18.4%.

By the use of either of these acids the effect above outlined on the ground fabric is produced and of course any Variations of these concentrations and of the combinations of acids may be possible, but having actually used the acids dis.

closed in the Heberlein and Schuttig patents above referred to, I know that such acids will convert the cotton fibers of the base of the fabric into a permanent finish, that is, into transparent and resilient fibers as distinguished from dull,

translucent or truly ',archmentized fibers.

Retdrder.-'I 'his mayP be any of which 75 '.Or I may use mixed acid consisting of 1% nime and 99% suiphuric A(66%), the n mixture being diluted to 56 B. When this mixture is used it is permitted to act upon the ground by varying the nitric acid between the limits of .5% to 50% and between the limits'of 50 B to 57.5 B. The temperatures may vary from centigrade to 20 centigrade and the time of treatment may vary from 1 to 10 seconds. These.

combinations, too, will produce a -permanent finish as it is now known. When the caustic' soda is used, as will later appear, 50 B is preferable and its use on the ground fabric for'from .5 to 2 minutes at any temperaturesis preferable. Alkali-Caustic alkali such as caustic soda.

Fabric- Onefabric` (A) that I contemplatev subjecting to my process to produce the ultimate fabric, is a cotton fabric such as cotton marquisette, `which has .pattern or` figure forming portions raised from and extending from'the obverse side of the fabric, which portions are interengaging with the ground threads of the fabric.

These raised portions may either be cottonvor wool or silk, or any other substance that' would normally be susceptible to lacidor alkali, and in 1 contemplate' treating either of the above fanrlries after they havebeen mercerized or subjected to the action of a caustic alkali.

Neuhausen- Any well known neutralizer may beused. Supposing now that an unbleached and unmercerized, fabric offthe character of the fabric (A) above, is to be subjected to all of the steps disfabric but will not be permitted to penetrate the raised patternor figure forming portions.l vAfter the drying of the fabric in the dryer 9, the fabric passes on and o'ver andin contact with a roller Il, which is submerged in an acid Ibath- (of any of the acids hereinbefore referred to) in a tank Il. Thus'the acid is applied to the back ofthe vvfabric and its penetration. intothe raised pattern or figure forming portions 2 is repelled by the retarder, with the-result that the ground fabric is subjected to the action of the acid but the raised pattern or figure forming portions are not.

The entire fabric is then plunged into a watery bath in a tank I2, passing around rollers I3 and Il, or it is subjected to a spray washing by a sprayer I5 before theacid reaches the raised or pattern forming-portions on the obverse side of lthe ground. The effect of this is to wash the the cellulose.

acid from the fabric and arrest its reaction with 0f course this reaction may be arrested also by subjecting the fabric to a neu tralizing agent,l either with or without the presence of water. The time intervalintervening between the application of the acid to tbe-fabric and the neutralizing of the acid or the washing of the acid from the fabric must 'be such that a chemical reaction will take place betweenthe acidand the cellulose of the fabricground to closed in the .drawings and outlined heretofore Ain the specification, the fabric is .moved con,

tinuously, preferably in a rdirection indicated `from right to left in Figure 1 of-the drawings so that theraised pattern or figure forming por;

such an extent that the chemical character of the oliltside of /the cotton bers Will be altered by the reaction and yet an unaltered core will be retained. If the entire cotton is altered chemically by this reaction the strength and flexibility ofu the fabric will be destroyed. The strength dependsupon the presence of some unaltered cotton and i-t is for this reason that an unalteredn core must be retained. Of course the degree of penetration and of reactiondetermines'- the degree o f transparency and the time interveningbetween the application of the' acid and the arresting of the reaction is governed somewhat by the de sire `of the operator and the transparency requirement.

, It has been found that, for instance, sulphuric Y tions 2are on the upper'side of the fabric. The

retarder is first` applied to the fibers from which the pattern or figure forming'portio'ns are 'made as for instance by passing the fabric first be-v neath a retarder applicator 4', which'is so constructed that it will apply a retarder of a type hereinbefore disclosed to the upper portions only of the pattern or gure forming portions 2 of the fabric. This may be accomplishedyfor instance,

air dryer 6. The time interval between the application of the retarder and the drying of the fabric in the dryer 6 is such that the penetration of the retarder will be arrested in the raised pattern or figure forming portions, and the retarder will be prevented from penetrating into the ground portioni of the fabric.A

The fabric'thcn passes on and the ground fabric is subjected to'an accelerator of a type herein.- fore disclosed. Thisis accomplished by hav- 1 the fabric pass over the periphery of a roller that is submerged in the acceleratorof the ype described -in a ltank l. The fabric then on 4to a similar dryer 9,'the time interval tween the applicationlof theac'celerator to the ack of the base fabric and the drying of thel abric in the dryer 9 'being such that the accelf rator will be permitted to penetrate the base by a wick 5. The fabric is then passed through a dryer of arrv well known type, such as a hot acid at 54.-B. may be allowed to react with the cotton or cellulose for about five seconds without destroying the strength or the resiliency of the cotton. This is disclosed in the Heberlein patent above referred to. The Schuttig patent above referred to also discloses the rapidity with which the reaction must bearrested when the Schuttig acid is used.

From the washer I2 the fabric passes through a dryer I6 and then again beneath a retarder I1 Aof the character-of the retarder 4 and which operates in a similar manner. It passes then through a dryer i8 which dries the fabric in the manner described in connection with the dryer 6. From the dryer I8 the fabric passes over a vroller I8 in a tank 20, which'contains anaccelerator and which roller I! acts in the same manner as the roller 1 previously described plication of the retarderfrom the sour-cel and the drying of the fabric in the dryer 6, and thev time intervening between the application of the accelerator bythe roll I9 and the drying of the fabric'in the dryer 2l being substantially the A same as that intervening between the applica- The fabric then tion of the accelerator by the roll 1 andthe drying of the fabric in the dryer 9.

After the fabric leaves the dryer 2l it passes over a roller 22 which is located in a tank 23, which latter vcontains a caustic alkali. The caustic alkali is applied to the back of the ground l of the Vfabric as the fabric travels over and in contact with the roller 22. The fabric is then washed in awash tank 24, the lfabric passing over rollers 25 and 25 and either being sub-v merged in water containedin the tank or subjected to a spray of water from a spray head 21. Of course the time intervening between the application of the alkali by the roller 22 and the washing of the alkali from the'fabric or the arresting of its action upon ythe fabric being such that the alkali will be permitted to react with the ground fabric but will be prevented from reacting with the raised pattern or. figure formor iigureforming portions in amanner which has previously been described and then the fabric is passed through a' dryer 39 to arrest the travel of the retarder.. the time interval between theapplication of the retarder and the drying of the fabric at this Apoint being' substantially the same as that intervening between the application of` the retarderby the applicator I and the drying of the fabricin the dryer'.

The fabric then `again passes over a roller 3l in a tank 32 containing anaccelerator. In this passage the back of the fabric .contacts with the periphery of the roller and the accelerator is applied. The fabric then passes through a dryer 33 where the fabric is dried and the action of the accelerator arrested. The time interval here between the application of the accelerator and the drying of the fabric is substantially the same as between-the application of the accelerator by the roller 'I and the drying of the fabric in the dryer 9. From the, dryer 33 the fabric then passes over aroller-'34 in a tank containing any one of the acids or mixtures hereinbefore referred to. As the fabric passes over in contact with the face of this roller 34, the acid is applied to the back of the fabric. then subjected to the action of the water gin tank 35 passing over the rollers 36 and 31 or to the action ofv water from a spray head 39, the time intervening between theapplication of the acid by the rollerand the" arresting of its action in the tank l2.

Thefabric then passes through a dryer 39 'where it is dried. f-Up'to this 'point the fabric has been subjected 'first to the action of an acid then `an alkali.,v and then anacid, which results, as

set forth in the two patents above mentioned, in the chemical change in the cellulose of the fabric ground, imparting to the fabric ground what is known as a permanent finish wherein it is characterlzed by'the fact that the cotton fibers have been valtered tobe substantially Ytransparent and resilient, as distinguished from a dull, translucent ortruly parchmentized fabric. This permanentv finish imparts a crispness and resiliency to thefabric and gives it what is known as a hand.

l But up to this time-the raised pattern or figure 20 tarders and accelerators. It is not necessary forming portions have been subjected to 'no chemical reaction 'so that they retain their original chemical composition and mechanical form. 'Ihus we have Va fabric the ground of 'which has been chemically altered to alter its physical characteristics and the raised. pattern or figure forming' portions of which have not been chemically altered and retain. their original physical characteristics. The fabric may be subjected to any Washing operation as any ordinary permanent finished fabric suchas permanent organdie or permanent marquisette, bothv of which and many similar types ofjfabric may be treated by this method.

Of course it is to be understood that instead of using Water in the tanks I2. 2A and 35, neutralizingagents may b e used and these may be any well known agents. The acidsumay be such a@ I have heretofore described or their equivalents, as may likewise be the alkalis and the rethat I'apply theretarders and= accelerators as often as I have heretofore described, for they may be' so applied that one application will last through several of the succeeding operations.

I Thus it is possible to omit the application -of the retarder by the applicator l1 for instance, or in soine instances it may be possible to omit the application of the retarder by the applicator I'l and the applicator 29. Likewise it may be possible lto omit the application of the accelerator by the roller I9 or the application of the accelerator by the rollers I9 and 3i. The inclusion or the omission of these steps is dependent upon the lasting -qualities of the retarders and accelerators used under the conditions to which they are sub j'ected.

Moreover,` instead of applying acid-alkaliacid I may apply a-lkali-acid-alkali, in which latter l case thealkali will be contained in the tank Il,

- the acid'in the tank 23 and the alkali in the tank *Y like a linen finish.' Ther fabric is in which the roller 34 is mounted, the other operations remaining the same. Indeed, I may \on1it one of the acid steps and apply only acidalkali, in which instance the tank 35 and its associated parts will be omitted.

Moreover I have found that one acid applica- .tion alone produces aA desirable finish and when using-this the second acid step .will be omitted. When one acid step alone is used we get a permanent nish which is somewhat duller than the finish I have above described and is somewhat After the fabric leaves the dryer 39 is then subjected to the vnal finishing operations whichconsist in subjecting the pattern or ligure 'forming portions,4 to a ufling action which may either be by mechanical contact or with compressed 'fluid'suchas air "orsteam, or may be a combinatiorr of both. In the drawings I have illustrated a preliminary ufling operation which consists in uing the pattern or figure forming portions 4bymeans of a rotary brush 49 which engages the pattern or figure forming portions and flufl's them so that their ends extend away from the obverse side of the fabric.

T he .pattern or gure forming portions may be subJected to a uing operation prior to the entry of the fabric beneath the first retarder appli- `cator 4 if this is found desirable. f

After the fabric leaves the fluffer 40 it then passes over -a roller Il which operates in a tank 42 containing moisture so that the ground4 ofthe fabric alone is moistened. The purpose of this moistening is to permit the fabric to be stretched into form by the tenter frame I3. After the fabric leaves the moistener M it is engaged with the usual tenter frame 43 and is carried along by said frame which moves in the usual manner. This tenter frame passes into a heating zone or chamber 44 and the fabric passes over a platen 45. As the fabric passes over the platen it passes beneath fluid pressure iets 46 which project fluid under pressure on to the obverse side of the fabric. 'Ihis fluid may be steam, air or any gas, and the purpose of the projection is to further and finally fluff the raised pattern or figure forming portions Whether they be in the form of spaced dots -or other configurations.. From this uflng operation the fabric passes on to the usual packing operation.

In the above description I have shown how the process in its entirety is applicable to the finishing of unbleached and unmercerized fabric of the (A) class above.

Of course the same steps may be used in connection with the (B) fabric above described.

The same 'is also true of either the (A) or the (B) fabrics when they have been bleached prior to the carrying on of this process. The bleaching, however, when a bleachsuch as a peroxide bleach is used, will fluff the pattern or figure forming portions before they are subjected to the instant process as this ufng is incident to the bleaching.

However, when either the (A) or (B) fabrics have been mercerized prior to being subjected' to the instant process it is not necessary 'to use an acid-alkali-acid treatment', such as has been described because the mercerizing replaces one of these steps and I have found it desirable to use merely an acid-alkali treatment such asA described in the Schuttig patent hereinbefore referred to. This in effect gives us an alkali-acidalkali treatment with the initial alkali treatment taking place as a separate operation.

Of course many subcombinations of this en- (24), and (25),v and f ground and unfinished groups of fibers on the tire combination of steps are possible within the scope of this invention.

The outstanding steps that are essential are the treating of the base fabric to alter the chemy ical composition thereof without altering the physical appearance of the pattern or figure forming portions that protrude from the obverse side of the ground. The treatment of the ground fabric may vary in many subcombinations of this general process and the ground fabric may have the accelerator applied while at the same time the retarder is applied to the pattern or figure forming portions. Onthe other hand, the accelerator may be omitted and the retarder applied. Moreover, the retarder may be omitted and the accelerator applied, or both ,may be omitted. Of course, regardless of the treatment of the ground fabric and the raised pattern or figure forming portions by the entire process or any subcombination thereof, steps 22, 23, 24 and 25 may be either used or omitted depending upon the condition in which it is desired to leave the pattern or figure forming portions.

I have found that a satisfactory fabric is produced by using all of the twenty-five operations hereinbefore described, and this when either the acid disclosed in the Heberlein patent above re- ;ferred to or the Schuttig patent above'vrefer'red to is used. I have also found that a satisfactory fabric is produced when the following operations alone are followed (referring to these operations by the numbers attributed to them on the drawings): (I`), (9), (l0), (Il),

acids above referred to I have-heretofore stated, the process is not to be limited to this combination or subcombination.

The treatment of the ground fabric with the acid disclosed in the Heberlein'patent probably results in the conversion'of the bers (except the cores thereof) into a cellulose sulphate, while the treatment with the acid disclosed in the Schuttig patent probably results in the conversion of the cotton fibers (except the cores thereof) into a cellulose nitrate.

It is to be understood that the mechanism herein disclosed is only a conventional representation of how the method may be carried out for other mechanisms may be used and indeed the method may be carried out by hand.

' What I claim is:

l. The method of treating cotton fabric that includes an open mesh ground and spaced groups of yarn or roving fibers engaged with the ground and having free ends extending away from the obverse side of the ground and bight portions engaged with certain of the threads of the ground to produce a fabric having a"permanent finish obverse side of the ground, which includes the steps of: subjecting the ground to successive treatments of acid and alkali capable of producing a permanent relatively transparent and stiff finish, and arresting the actions of said acid and alkali before the character of the free endsxof the fibers is affected by rendering said acid and alkali chemically inactive in situ.

2. The method of treating cotton fabric that includes an open mesh ground and spaced groups of yarn or roving fibers engaged with the ground and having free ends extending away from the obverse side of the ground and bight portions engaged with certain of the threads of the ground to produce a fabric having a permanent finish ground and unfinished groups of fibers on the obverse side of the ground, which includes the steps of z' subjecting the ground to the successive treatments of acid and alkali capable of producing a permanent, relatively transparent and stiff finish, and arresting the successive actions of the acid and alkali by neutralization before the acid or alkali affects the free ends of the fibers whereby the original character of said free ends is preserved.

3. The method of treating cotton fabric that includes an open mesh ground and spaced groups of yarn or roving fibers engaged with the ground and having free ends extending away from the l obverse side of the ground and bight portions of 'said fibers to produce a uffy appearance of spaced groups thereof.

4. 'I'he method of treatingcotton fabric that Y includes anopen mesh ground and spaced 1groups of yarn or roving fibers engaged with the ground and having free ends extending away from the obverse side of the ground and bight portions engaged with certain of the threads of the ground to produce a fabric having a permanent finish ground and unfinished" groups of fibers un the obverse side -of the ground, which includes the steps of: subjecting the ground to a chemical re- I action capable of producing a permanent, relatively transparent and stiff ground and arresting the said chemical reaction before it affects the original character of the free ends of the fibers by rendering the chemical inactive in situ, and fiuing said free ends to form iiuffed up and spaced groups of fibers on the obverse side of the ground whereby the free ends of said groups of fibers are unfinished and'the ground is per manently finish .'v' l 5. The method of treating cotton fabric that includes an open mesh ground and spaced groups of yarn or roving fibers engaged with the ground and having free ends extending away from the obverse side of the ground and bight portions engaged with certain of the threads of the ground to produce a fabric having a permanent finish ground and unfinished groups of fibers on the obverse side of the ground, which includes the steps of: subjecting the ground to the successive treatments of acid and alkali capable of producing a permanentrelative1y transparent and stiff finish, and arresting the successive actions of the acid and alkali' by dilution before the acid or alkali affects the free ends of the fibers'whereby the original character4 of said free ends is preserved.

6. The method of treating cotton fabric as recited in claim l wherein before the groundis subjected to the acid and alkali treatments a retarder is applied to the fibers from which the groupsY of fibers are formed.

7. The method 'of treating cotton fabric as recited in claim 2 wherein before the ground is subjected to the acid and alkali treatments a4 retarderis applied'to the fibers from which the groups of fibers are formed.

8. The method of treating cotton fabric as recited in claim 3 wherein before the ground is subjected to the acid and alkali treatments a retarder is applied to the fibers from which the groups of fibers are formed.

9. The method of treating cotton fabric as recited in claim 4 wherein before the ground is subjected to said chemical reaction a retarder is applied to the fibers from which the groups of fibers are formed.

10. The method of treating cotton fabric as recited in claim 5 wherein before the ground 1s subjected to the acid and alkali treatments a retarder is applied tqthe bers from which th groups of fibers are formed.

CLARENCE T. GRAHAM.

' CLARENCE T. GRAHAM.

It is hereby certified that error appears 4in the' printed specification ofthe above' nunbe'redpatent requiring correction aes-follows: Page 2, sec'- ond column, line 1|.'6, for "transparent". read .trans1uc ent^; pnge, 4suecond column, line 62, for roller 18" read-roller 19; and that the said Letters Patent should be .read with this correction thorein'that the same may conform to the record of the caso in'the Patent .Offices sigma ma sealed this 23th any or Apr11,A.. D. 191m.

t ,Henryvan Aradale (Seal) I Acting Commissioner of Patents. 

